• Title/Summary/Keyword: Cellular systems

Search Result 1,294, Processing Time 0.032 seconds

ARCA-An Adaptive Routing Protocol for Converged Ad-Hoc and Cellular Networks

  • Wu, Yumin;Yang, Kun;Chen, Hsiao-Hwa
    • Journal of Communications and Networks
    • /
    • v.8 no.4
    • /
    • pp.422-431
    • /
    • 2006
  • This paper proposes an adaptive routing protocol called ARCA for converged ad-hoc and cellular network (CACN). Due to the limitation of both bandwidth and transmission range in a cell, a mobile host (MH) may not be able to make a call during busy time. CACN offers a flexible traffic diversion mechanism that allows a MH to use the bandwidth in another cell to ease the congestion problem and increase the throughput in a cellular network. Based on the presentation of CACN's physical characteristics, the paper details the design issues and operation of the adaptive routing protocol for CACN (ARCA). Detailed numerical analysis is presented in terms of both route request rejection rate and routing overhead, which, along with the simulation results, have indicated the effectiveness and efficiency of the ARCA protocol.

Current Challenges of Streptococcus Infection and Effective Molecular, Cellular, and Environmental Control Methods in Aquaculture

  • Mishra, Anshuman;Nam, Gyu-Hwi;Gim, Jeong-An;Lee, Hee-Eun;Jo, Ara;Kim, Heui-Soo
    • Molecules and Cells
    • /
    • v.41 no.6
    • /
    • pp.495-505
    • /
    • 2018
  • Several bacterial etiological agents of streptococcal disease have been associated with fish mortality and serious global economic loss. Bacterial identification based on biochemical, molecular, and phenotypic methods has been routinely used, along with assessment of morphological analyses. Among these, the molecular method of 16S rRNA sequencing is reliable, but presently, advanced genomics are preferred over other traditional identification methodologies. This review highlights the geographical variation in strains, their relatedness, as well as the complexity of diagnosis, pathogenesis, and various control methods of streptococcal infections. Several limitations, from diagnosis to control, have been reported, which make prevention and containment of streptococcal disease difficult. In this review, we discuss the challenges in diagnosis, pathogenesis, and control methods and suggest appropriate molecular (comparative genomics), cellular, and environmental solutions from among the best available possibilities.

The Design and Implementation of Interference Canceller Systems in the Environments with Co-existing ETACS and CDMA Digital Cellular Systems (ETACS와 CDMA 디지털 셀룰라 시스템이 공존하는 환경에서 Interference Canceller System의 설계 및 구현)

  • Jang, Won-Ho;Hong, Ju-Seok;Lee, Yun-Hyun
    • Journal of Advanced Navigation Technology
    • /
    • v.6 no.4
    • /
    • pp.273-278
    • /
    • 2002
  • In this paper, we provide the Interference Canceller Systems(ICS) in the wireless environments in the presence of co-existing ETACS and CDMA digital cellular systems to effectively cancel the interference than the established canceller systems. We proved the enhanced cancelling performances more than 29 dB cancellation characteristics between co-existing ETACS and CDMA digital cellular systems and the stabilized system characteristics in the rapidly changing wireless circumstances.

  • PDF

A Study on the Formation of Cellular Manufacturing Line for Construction JIT System's Basis (JIT 시스템 운용의 출발점 - Cellular 제조라인의 구축)

  • 구일섭;신현표
    • Journal of Korean Society of Industrial and Systems Engineering
    • /
    • v.17 no.31
    • /
    • pp.43-48
    • /
    • 1994
  • In an effort to become more competitive and cost efficient many companies have shifted from traditional job-shop production to production using group technology (GT) and cell manufacturing (CM). Cellular manufacturing is critical to implementing Just-in-Time (JIT) production which pointed out in the previous articles. and adopt the U-shaped cell which allows for entry at one end of the U and exist at the other. This paper looks at the availability of cellular manufacturing, by applying those concepts to the small and medium sized industry.

  • PDF

A Study on Cellular Communication with Frequency Hopping Technique (주파수 도약 기술을 이용한 셀루라 통신에 관한 연구)

  • 진봉철;박상규;한영열
    • The Journal of Korean Institute of Communications and Information Sciences
    • /
    • v.16 no.6
    • /
    • pp.517-532
    • /
    • 1991
  • This paper shows performance analysis for FH/MF나 systems over the cellular mobile communication channel. The Channel capacity over FH/MF나 system is represented as a function of deletion probalblity (Po) and insertion probalbility(Pt). The spectral efficiency of the system serves as a per formance of cellular system is inferior to that of non cellular system. In the case of frequency reuse, we get the best performance when the reuse pattern(N) is 3.

  • PDF

An Intergrated Framework for a Cellular Manufacturing System (셀 생산 시스템의 통합 구조)

  • 임춘우;이노성
    • Journal of Korean Society of Industrial and Systems Engineering
    • /
    • v.20 no.43
    • /
    • pp.219-228
    • /
    • 1997
  • The objective of this paper is to provide an alternative framework for the integration of process planning and scheduling in cellular manufacturing. The concept of an integrated cellular manufacturing system is defined and the system architecture is presented. In an integrated cellular manufacturing system, there are three modules : the process planning module, the manufacturing-cell design module, and the cell-scheduling module. For each module, the tasks and their activities are explained.

  • PDF

Modification of Existing Similarity Coefficients by Considering an Operation Sequence Ratio in Designing Cellular Manufacturing Systems

  • Yin, Yong;Yasuda, Kazuhiko
    • Industrial Engineering and Management Systems
    • /
    • v.1 no.1
    • /
    • pp.19-28
    • /
    • 2002
  • An operation sequence of parts is one of the most important production factors in the design of cellular manufacturing systems. Many similarity coefficient method (SCM) based approaches have been proposed to solve cell formation problems in the literature. However, most of them do not consider the operation sequence factor. This study presents an operation sequence ratio (OSR) and modifies some existing similarity coefficients using the OSR to solver cell formation problems considering operation sequences. The computational results show that the OSR ratio is useful and robust in solving cell formation problems with operation sequences.

Inter-Cell Interference Coordination Scheme for OFDM-based 4G Cellular Systems (OFDM 기반의 4G 셀룰러 시스템을 위한 인접 셀간의 간섭 조정 기법)

  • Yoon, Gil-San;Lee, Jeong-Hwan;Cho, In-Sik;Seo, Chang-Woo;You, Cheol-Woo;Hwang, In-Tae
    • Journal of the Institute of Electronics Engineers of Korea TC
    • /
    • v.46 no.8
    • /
    • pp.16-21
    • /
    • 2009
  • OFDM is a key technology for 4G cellular systems in the future. But when OFDM is used in cellular system environment, it has severe inter-cell interference problems. In this paper, we propose an ICIC scheme that can reduce inter-cell interference for OFDM-based 4G cellular systems. and we analyze the efficiency of the proposed scheme. Simulation is carried out according to the simplified 3GPP LTE system level simulation parameters. We have confirmed the improvement of Geometry efficiency about 4dB at the results.

An Inter-Cell Interference Estimation Algorithm for Cellular OFDMA Systems (셀률러 OFDMA 시스템을 위한 셀간 간섭추정 알고리즘)

  • Rim, Min-Joong
    • Journal of the Institute of Electronics Engineers of Korea TC
    • /
    • v.43 no.10 s.352
    • /
    • pp.55-59
    • /
    • 2006
  • In cellular OFDMA(Orthogonal Frequency Division Multiple Access) systems, each subcarrier may suffer from different amount of interferences from neighbor cells. Suppose that it is possible to accurately estimate inter-cell interferences for each subcarrier, the performance can be considerably improved by applying SINR(Signal to Interference and Noise Ratio) weighting. This paper proposes an inter-cell interference estimation method for cellular OFDMA systems. The proposed method extracts amounts of noise and interferencesby eliminating the channel variation effects of pilot symbols caused by frequency offset, timing offset mobile velocity, and delay spread.